This invention relates to a silver halide photographic light-sensitive material and particularly to a silver halide photographic light-sensitive material high in photosensitivity, low in fog, without producing any residual color-contamination and excellent in aging stability.
In recent years, a silver halide photographic light-sensitive material has been required to have a rapid processability as well as a high photosensitivity and a high image-quality. Particularly, with a photographic light-sensitive material for medically diagnostic use, an image information has been required to be high in photosensitivity and an image sharpness within a short period of time when diagnosing the illness of a patient.
Heretofore, many proposals for increasing the photosensitivity of a silver halide emulsion have been made so far. For example, Japanese Patent Open to Public Inspection (hereinafter referred to as JP OPI Publication) No. 63-305343/1988 discloses that a spectral sensitivity is increased by adding a sensitizing dye before carrying out a chemical ripening treatment and a development speed is accelerated at the same time.
However, in a rapid processing treatment, each of the time for fixing and washing treatments is shortened. Therefore, there raises such a problem that an sensitizing dye contained in a light-sensitive material is not dissolved out, so that it remains as a residual color-contamination. When reducing an amount of such a dye as mentioned above, a residual color-contamination may be avoided. However, it is not preferable because the photosensitivity of the subject light-sensitive material is lowered.
On the other hand, well-known processes for chemically sensitizing silver halide grains include, for example, a selenium sensitization in which a selenium compound is used, as well as a sulfur sensitization, a noble-metal sensitization and a reduction sensitization.
In the above-mentioned selenium sensitization process, however, on the other hand of the fact that a high photosensitivity can be obtained as compared to the other sensitization processes, there is such a defect that the raw stock preservability of a light-sensitive material cannot be excellent, so that a fog may be increasingly produced. Therefore, a further improvement thereof has been requested so far.